GB2176943A

GB2176943A - Electric drive unit

Info

Publication number: GB2176943A
Application number: GB08614247A
Authority: GB
Inventors: Klaus Frohmuller
Original assignee: Licentia Patent Verwaltungs GmbH
Current assignee: Licentia Patent Verwaltungs GmbH
Priority date: 1985-06-14
Filing date: 1986-06-11
Publication date: 1987-01-07
Also published as: GB2176943B; GB8614247D0; IT1189556B; DE3521342C1; FR2587555B1; FR2587555A1; IT8620789A0; IT8620789A1

Abstract

An electric drive unit comprising a motor housing (11) with a motor, and a gear (29) which is drivably coupled to the motor and the housing of which comprises a pot-shaped base part (23) and a cover part (25) mounted thereon and is received in an axially projecting wall portion (12) of the motor housing (11). The projecting wail portion (12) and the base part (22) of the gear housing each have a plurality of securing tabs (33, 38) which project into a corresponding number of openings of the cover part (25). The gear housing tabs (33) are received in radially inner portions of the openings and the motor housing tabs (38) in radially outer portions of the openings, the tabs being fastened in the openings. Alternatively (Figure 6) base part is constructed as a closed trough shaped component containing lubricant cover and motor housing be secured together as above. <IMAGE>

Description

SPECIFICATION Electric drive unit The present invention relates to an electric drive unit.

In the case of an electricmotorwithdrivably coupled gear, the gear can be disposed in a separate housing which is received at a drive output end of the motor by a projecting wall portion,forming a receptacle, ofthe motor housing. It is desirablethat the parts of the motor which receive the gearshould be able to be produced with relatively little effortand also that the assembly ofthese parts should be ableto be performed in simple manner. In particular, a simple, reliable and accuratelyfitting connection producible with little effort between motor and gear housing should be possible.

According to the present invention there is provided an etectricdrive unit which comprises a motor housing receiving an electric motor and having a wall portion which projects in the axial direction of the motor at a drive output end thereof and is provided at its free end with a plurality offirst securing tabs, and a gear housing which is received in the projecting wall portion and receives a gear drivably coupled to the motor,the gear housing comprising a generally pot-shaped base member provided with a corresponding plurality of second securing tabs and cover member provided with a corresponding plurality of openings each having a radially inner portion receiving a respective one ofthe second tabs and a radially inner portion receiving a respective one of the first tabs, the first and second tabs being fastened at the cover member.

The gear housing, comprising a post-shaped base memberandacover member, can be assembled before the insertion into the receptacle formed by the projecting wall portion, namely in such a mannerthat the axially protruding end tabs at spacer arms ofthe base member are inserted into main portions of the openingsofthecovermemberand possiblyalso fastened therein at that time. Thereafter,the resulting gear housing is inserted into the receptacle formed by the projecting wall portion ofthe motor housing and in such a mannerthatthe corresponding tabs, protruding in axial direction ofthe motor, ofthewall portion of the motor housing engage into additional portions ofthe openings of the cover member.

Thereafter, the tabs of the motor housing, and optionally also, the tabs ofthe base member ofthe gear housing arefastened in the openings, for example bywedging.This provides a simple, easily performed and reliable fastening between gear housing and motor housing. An additional stability can result ifthe bent-over spacer arms bear attheir outer sides against the inner side ofthe projecting wall portion ofthe motor housing. Afurther stabilisation can be achieved if the base member part has additional support arms which, in the assembled state, bear against a bearing end plate of the motor and determinethespacing between motor and gear.

The gear housing can be simply and easily produced. The starting material can be merely two planar plates orround discs, namelyforthe cover member and the base member, which before the bending over at right angles ofthe spacer arms and support arms has the form of a planarpartwith punched-out straps. The pot-shape of the base member arises after bending-over ofthe spacer arms.

The bent spacer arms take over the function of centring, fastening and spacing between the cover member and the base member. Fastening bolts, which are usually employed in gear housings ofthat kind, are thus no longer required.

The additional opening portions, disposed radially outside the main portions ofthe openings,forthe reception and wedging of the tabs of the motor housing have a circumferential extent which is preferably smallerthan that ofthe main portions of the openings. This fact has the effect that the spacer arm tabs, which are wedged in the main portions of the openings, cannot deviate into these additional portions ofthe openings.

Embodiments ofthe present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Figure lisa longitudinal sectional view, along the line l-l of Figure 2,of a first geared motor unit embodying the invention; Figure2 is an end view ofthe unit in the direction A according to Figure 1; Figure 3 is a view of a punched-out base part of a gear housing before the bending into final shape; Figures4and5areviewsoftabopeningsandtabs in the unit of Figure land Figure 6is a view, similarto Figure 1, ofa second geared motor unit embodying the invention.

Referring now to the drawings, there is shown in Figure 1 a geared motor 10 comprising a motor housing 11 which at a drive output end (indicated by arrow A) forms a receptacle by means of an axially projecting wall portion 12. The housing 11 contains a motorwith a shaft 13, a rotor 14, short-circuit rings 15, a stator 16 and stator winding heads 17. The shaft 13 is mounted byway oftwo bearings 18 and 19, which are seated in bearing plates 20 and 21. The drive output end of the shaft 13 is designated by 22.

Received in the receptacle of the motor housing 11 is a gear housing which comprises a pot-shaped base part 23 with a base plate 24, and a cover part 25.

Seated in the parts 24and 25 are two bearings 26 and 27 for a gear shaft 28, a toothed wheel 29 of which stands in meshing engagement with a pinion ofthe output end 22 ofthe shaft 13. The bearings 26 and 27 are seated in spoke-shaped parts 30 of the base plate 24 and the cover part 25. The base plate 24 has an opening 31 for the passage of the motor shaft 1 3.

In the embodiment of Figure 1, the pot-shaped base part 23 is formed from a punched partwhich is illustrated in Figure 3 in its planar punched-out, but unbent, state. The punched part possesses spacer straps 32, which are arranged at right angles to each other and provided radially outwardly with end tabs or projections 33 and notches 34. For connection with the cover part 25, the spacer straps 32 are bent over at right angles at bending lines or edges 43 and wedged in -main opening portions 35 of the cover part25.

Provided radially outwards of the main opening portions 35 are additional opening portions 36 for the fastening of the motor housing 11 to the cover part 25.

For this purpose, the projecting parts 12 of the motor housing are provided with tabs or projections 38 which have notches 39 and are wedged in the additional opening portions 36. The main and additional opening portions 35 and 36 are disposed in punched ears 37 ofthe cover part 25.

Designated by40 are punched supporting straps which are bent over at right angles in direction 41 and the end faces 42 of which bear against the plate 20.

The support straps 40 lie between the spacer straps 32. Bending lines ofthe support straps are designated by 44.

Figure5showspartofthehousing 11 withoneof the projections 38, which fits into the additional opening portion 36 of the cover part 25 in Figure 4.

Figure 6 shows an embodiment which generally corresponds with Figure 1 but in which the gear housing is built up differently. In this embodiment, the housing base part 23' is constructed as a closed, trough-shaped component which has only the cover plate opening and an opening 31 ' for passage of the shaft end 22. Fastening with the cover part 25' and the motor housing 11 takes place in the same manneras forthe first embodiment. A disc-shaped seal 45 is provided between the cover part 25' and the base part 23'. The opening 31' is similarly provided with a seal 46. This gear housing is, for example, produced from a casting and can,forexample, be filled with oil in view of the complete sealing. A plastics material part 47 can fill out the gear housing region which contain no parts to be lubricated. Thereby, lubricant oil and weight can be saved. Atacho-generator is designated by 48. The geared motor 10 can be fastened two a device to be driven by means ofthreaded fastening bores 49 in the cover part 25 or 25'.

Claims

1. An electric drive unit which comprises a motor housing receiving an electric motor and having a wall portion which projects in the axial direction ofthe motor at a drive output end thereof and is provided at its free end with a plurality of first securing tabs, and a gear housing which is received in the projecting wall portion and receives a gear drivably coupled to the motor, the gear housing comprising a generally pot-shaped base member provided with a corresponding plurality of second securing tabs and a cover member provided with a corresponding plurality of openings each having a radially inner portion receiving a respective one of the second tabs and a radially outer portion receiving a respective one of the firsttabs, the first and second tabs being fastened atthe cover member.

2. Aunitas claimed in claim 1,wherein the radially outer portion of each of the openings is smaller in the circumferential direction ofthe cover member than the radially inner portion ofthat opening.

3. Aunit as claimed in either claim 1 or claim 2, wherein the base member comprises a base plate and a plurality of spacer arms which are formed integrally with and bent to extend at right angles to the base plate, the second tabs being disposed atthe free ends ofthe spacer arms.

4. A unit as claimed in claim a, wherein the base member further comprises a plurality of support arms which are formed integrally with and bentto extend at right angles to the base plate and which are arranged between the spacer arms, the support arms extending in the opposite direction to the spacer arms and bearing attheirfree ends against an end wall plate of the motor housing.

5. A unit as claimed in claim 4, comprising four such spacer arms arranged at uniform spacings from each other and four such support arms arranged at uniform spacings from each other, each of the support arms being disposed between and equidistantly spaced from two of the spacer arms.

6. A unit as claimed in anyone ofthe preceding claims, wherein each of the openings is provided in a radially projecting ear of the cover member.

7. A unit as claimed in either claim 1 orclaim 2, wherein the base member comprises a base plate with an aperture receiving an output shaft of the motor and a continuous peripheral wall projecting from the base plate, a shaft seal being arranged to seal the shaft relative to the base plate at the aperture and an end seal being arranged between the free end ofthe peripheral wall and the cover member.

8. Aunitasclaimed in any one of the preceding claims, wherein the cover member is provided with threaded fastening bores.

9. A unit as claimed in any one of the preceding claims, comprising a filler element arranged in the gear housing to reduce the internal volume thereof in a region spaced from parts to be lubricated.

10. A unit as claimed in anyone ofthe preceding claims, wherein each ofthe tabs is provided with notches and wedged in the respective one of the openings.

11. An electric drive unitsubstantially as herein- before described with reference to Figures 1 to 5 of the accompanying drawings.

12. An electric drive unit substantially as hereinbefore described with reference to Figure 6 of the accompanying drawings.